This is the 618th most frequent Greek word.
καθόλου
"Καθόλου" means "not at all" or "completely" depending on context.
The word 'καθόλου' contributes a negative emphasis to the verb, indicating a total lack of interest.
Δεν με ενδιαφέρει καθόλου.
I am not interested at all.
In this question, 'καθόλου' is used to inquire if there is any amount (even a little) of sugar available.
Έχω καθόλου ζάχαρη για να φτιάξω τσάι;
Do I have any sugar to make tea?
Here, 'καθόλου' is used to emphasize the absolute absence of problems, showing reassurance.